Answer:
Option A
The cost of keeping the semiconductor below the critical temperature is unreasonable
Explanation:
First of all, we need to understand what superconductors are. Superconductors are special materials that conduct electrical current with almost zero resistance. This means that there is little or no need for a voltage source to be connected to them. As a matter of fact, once a superconductor is connected to a power supply, one can remove the power supply and the current will still flow.
However, most superconducts can only conduct at very low temperatures up to -200 degrees Celcius. This is because, at that temperature, their atoms and molecules are relatively settled, hence they pose little or no resistance to the flow of current.
This as you can guess is extremely difficult to do, as you will need a lot of effort to cool it to that temperature and maintain it.
This makes option a the answer:
The cost of keeping the semiconductor below the critical temperature is unreasonable.
Answer:
a) 
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
a = Acceleration
The acceleration of the bicycle and rider is -1.5 m/s²
Force
The magnitude of the average force needed to bring the bicycle and its rider to a stop is
Words less true are seldom if ever spoken.
Answer:
Distance is path length covered by particle. When particle moves along half circle, it covers half the circumference therefore distance covered is (2×pi×r)/2 = pi× r. ... Hence displacement is equal to diameter or 2 times the radius of circle.
